1. Field of the Invention
This invention relates to a cable steering device in which a steering wheel and a gear box are connected to each other by flexible cables, such as Bowden cables.
2. Description of the Related Art
In a conventional steering device for a vehicle, a lower end of a steering shaft having a steering wheel at an upper end thereof is connected to a gear box so that a steering torque inputted to the steering wheel is transmitted to a rack and pinion mechanism provided in the gear box via the steering shaft.
However, when the steering wheel and the gear box are connected to each other using the steering shaft, it is difficult to freely select a position of the steering wheel relative to the gear box. Therefore, the degree of freedom of designing the apparatus is greatly restricted and further, the gear box cannot be commonly used in both a right-hand steered vehicle and left-hand steered vehicle. In addition, the vibration inputted from the road surface to tires and the vibration of an engine are inputted to the steering wheel via the steering shaft, so that such vibrations detract from calmness in the interior of the vehicle and riding comfort.
Therefore, a cable steering device employing flexible transmission means, such as Bowden cables instead of a conventional steering shaft has been proposed in Japanese Patent Application Laid-Open No. 8-2431.
When a steering device is formed in this manner, it becomes possible to freely select a position of a steering wheel relative to a gear box, and, moreover, the vibration of the gear box is rarely transmitted to the steering wheel. This solves the above-mentioned various problems.
A known electric power steering device is provided with an actuator, which comprises a power steering motor, on the outside of a gear box, and the wheels are steered by driving a steering rod housed in the gear box, by this actuator.
If a cable steering device and an electric power steering device are combined with each other with an actuator provided on a gear box, the degree of freedom of designing the electric power steering device with respect to the dimensions and shape thereof is reduced and it becomes difficult to place the electric power steering device in a narrow engine room.